Crude (unrefined) Animal and vegetable oils (referred to herein collectively as “natural oils”) are typically subjected to a variety of processing steps to remove specific undesirable components of the crude oil prior to sale. The type, number, and sequencing of processing steps can vary depending on the crude oil feedstock, refinery type (e.g. physical vs. alkaline) and configuration, target product markets, and the like. In general, crude natural oils are refined to remove excess quantities of “gums” (comprised primarily of phospholipids), free fatty acids, as well as various coloring components and volatile compounds.
Once removed from the crude oil, the refining byproducts are either sold directly into low-value markets such as animal feed, or further processed into higher-value products. Two major byproducts of the chemical refining processes of natural oils are soapstock and gums.
In most natural oil refineries utilizing the chemical refining process, phosphoric acid or an equivalent acid is added to the crude oil to increase the solubility of the phospholipids (gums) in water. Next, a strong base, typically sodium hydroxide (NaOH) is added, reacting with the free fatty acids in the oil to form soaps (salts of free fatty acids). Water is then added to the oil to remove the soaps and solubilized gums. Soapstock is typically acidulated to generate free fatty acids. Gums are typically sold into low-value animal feed markets or upgraded to food-grade emulsifiers, e.g. lecithin.
In most chemical refining configurations, additional waste streams are generated which represent low- or negative-value byproducts. For example, it typically necessary to perform an additional water wash on the oil after the majority of the gums and soaps have been removed. The lipid content of this washwater (referred to as Soapstock Makeup) can contain from about 5% to about 20% soaps and other lipids, but the lipid content is generally not sufficiently high to justify the costs of further processing into value added products. In addition, all of the above referenced byproduct streams from the chemical refining process contain various amounts of saponifiable material that are not converted to free fatty acids.
Nothing in the prior art provides the benefits attendant with the present invention. Therefore, it is an object of the present invention to provide an improvement which overcomes the inadequacies of the prior art methods and devices and which is a significant contribution to the advancement to realizing the full fatty acid yield of saponifiable material.
Another object of the present invention is to provide a method for generating free fatty acids from a mixed lipid feedstock, the method comprising: providing the mixed lipid feedstock; combining the mixed lipid feedstock with a base to form a mixture; allowing the mixture to react in a reaction vessel; introducing carbon dioxide into the reacted mixture in the reaction vessel to form a first carbonic acid within the reaction vessel; mixing the first carbonic acid and the reacted mixture within the reaction vessel; allowing the first carbonic acid and reacted mixture to settle within the reaction vessel; and draining a first aqueous layer from the reaction vessel.
Yet another object of the present invention is to provide a method for generating free fatty acids from a mixed lipid feedstock, the method comprising: providing the mixed lipid feedstock; combining the mixed lipid feedstock with a base to form a mixture; allowing the mixture to react in a reaction vessel; introducing carbon dioxide into the reacted mixture in the reaction vessel to form a first carbonic acid within the reaction vessel; mixing the first carbonic acid and the reacted mixture within the reaction vessel; allowing the first carbonic acid and reacted mixture to settle within the reaction vessel; draining a first aqueous layer from the reaction vessel; collecting the first aqueous layer; and treating the collected first aqueous layer with calcium oxides, magnesium oxides, barium oxides, or other polyvalent oxides.
Still yet another object of the present invention is to provide a method for generating free fatty acids from a mixed lipid feedstock, the method comprising: providing the mixed lipid feedstock; combining the mixed lipid feedstock with a base to form a first mixture; allowing the first mixture to react in a reaction vessel; combining the reacted first mixture with an organic or inorganic acid, thereby acidulating soaps in the first mixture to generate free fatty acids; draining a first aqueous layer from the reaction vessel; combining the generated free fatty acids with an alcohol to form a second mixture; and heating and pressurizing the second mixture to above the critical temperature and pressure of the alcohol, thereby esterifying substantially all of the free fatty acids to generate fatty acid alkyl esters.
Another object of the present invention is to provide a method for generating free fatty acids from a mixed lipid feedstock, the method comprising: a) providing the mixed lipid feedstock; b) combining the mixed lipid feedstock with a base to form a first mixture; c) allowing the first mixture to react in a reaction vessel; d) introducing carbon dioxide into the reacted mixture in the reaction vessel to form a first carbonic acid within the reaction vessel; e) mixing the first carbonic acid and the reacted mixture within the reaction vessel; f) allowing the first carbonic acid and reacted mixture to settle within the reaction vessel; g) draining a first aqueous layer from the reaction vessel; h) removing a generated lipid layer from the reaction vessel; and i) repeating steps a) through h) above up to 8 times using the generated lipid layer from the reaction vessel as the mixed lipid feedstock for step a).
Yet another object of the present invention is to provide a method for generating an animal feed additive from a mixed lipid feedstock, the method comprising: providing the mixed lipid feedstock; combining the mixed lipid feedstock with a base to form a mixture; allowing the mixture to react in a reaction vessel; introducing carbon dioxide into the reacted mixture in the reaction vessel to form a first carbonic acid within the reaction vessel; mixing the first carbonic acid and the reacted mixture within the reaction vessel; allowing the first carbonic acid and reacted mixture to settle within the reaction vessel; draining a first aqueous layer from the reaction vessel; and concentrating the first aqueous layer to generate a sodium bicarbonate product that is substantially free of any water.
The foregoing has outlined some of the pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.